Fall Grass Facts

If your horses are on pasture, then you’ve likely noticed some changes in the grass by this time of year (unless you live somewhere like Florida where the grass is green year-round!) But most grasses change over the course of the seasons, and therefore our grazing strategies often need some adjustment as well.

In this post, I thought I’d share a few fall grass facts that may be helpful for horse owners.

10 Fall Grass Facts

#1 As pasture grasses mature, their level of poorly fermentable fiber rises. This may decrease the level of digestible nutrients and lower the caloric value of the grass overall.

#2 Mature or dormant grass also has substantially lower protein content when compared to a lush, growing spring grasses.

#3 Mild temperatures along with fall rains may also cause a spike in grass growth. This, combined with cool nighttime temperatures (below 40 degrees F) increases sugar levels in mature grass and poses a laminitis risk for some horses.

#4 Grass also responds to cold stress by greatly increasing simple sugar and storage carbohydrate levels. This helps protect the plant cells from freezing but can wreak havoc with the micro-organisms in the horse’s large bowel.

#5 Grass covered in frost is likely too dangerous to allow insulin resistant horse to graze. The first frost is the most dangerous, but subsequent frosts may be less so (if grass has gone dormant).

#6 Overgrazed or low-quality pastures may lead horses to eat plants they wouldn’t normally touch, including poisonous ones. To make matters worse, some plants are at their most toxic in fall, including horse nettle, white snakeroot, and toxic fungus which can affect perennial ryegrass. Acorns eaten in large quantities can also pose problems.

#7 Cool season grasses such as timothy, brome, orchard grass, Kentucky bluegrass, and fescue usually continue to grow during cooler months while warm season grasses such as coastal Bermuda, buffalo grass, and Teff usually go dormant in fall.

#8 Once all grass has gone dormant (check to make sure no green grass is left beneath the brown grass), it is generally safe for metabolic horses to graze. (Of course, you will also need to feed hay at this time as brown grass provides little to nothing in the way of nutrition.)

#9 Since many pastures may become overgrazed by fall, it’s the perfect time to rotate pastures, use a sacrifice area, or put horses on a track system to keep them off the main pasture. Some people may choose to re-seed or fertilize pastures during the fall as well.

#10 Declining pasture quality in fall can be a serious issue for young growing horses, pregnant mares, and senior horses. Therefore, supplementing quality hay and concentrates is of particular importance for them.

Sources and Further Reading

Fall Pasture Warnings for You and Your Horse

Safe Autumn Grazing for Horses

Pasture Grass: The Healthy Choice

Pasture Management: How to Prepare for Fall